Thermoalarm



Sept. 10, 1929. F. G. FOLBERTH ET AL THERMOALARM Filed May 18, 1927 |NVENTOR W ATTORNEYS Patented Sept. 10, 1929.

UNITED STATES PATENT OFFICE.

'rHEnMoALARM. I I i Application filed May 18,

This invention relates to a signal device and is particularly applicable to a device for signaling when the temperature of the cooling fluid ofan automotive vehicle engine attains a predetermined point.

An object of the invention is to provide an improved signaling device which will emit an audible signal at predetermined temperatures.

Other objects will hereinafter appear.

The invention will be better understood from the description of three practical embodiments thereof,illustrated in the accompanying drawing, in which Fig. 1 is a central longitudinal section of one form of apparatusembodying theinvention;

Figs. 2 and 3 are central longitudinal sections, taken at right angles, of another embodiment thereof;

Fig. 4 is a central longitudinal section of a third embodiment thereof; and

Fig. 5 is a fragmentary sectional view similar to Fig. 2 of another embodiment.

In-Fig. 1, an automobile radiator cap is illustrated as comprising a tubular threaded portion 1 adapted to engage the usual'threads in the filling spout of an automobile radiator. Atthe upper end'of this tubular section is an outwardly extending flange Q'Carrying at its outer edge an upwardly extending tubular wall 3. Secured within and substantially filling the recess above flange'Q and'within wall 3 is a capsule preferably formed of thin 5 metal and having a normally concave upper end or head 5 and a substantially flat lower end or head 6.

The capsule contains a fluid 7 which is so chosen that itsboiling point is substantially the temperature which it is desired shall be indicated. The cap is attached to the filling spout of an automobile radiator in the usual manner and, of course, the lower head of the capsule iseXposed to the vapors within the radiator.

When the temperature within the radiator reaches that at which the fluid within the capsule vaporizes, vaporization takes place and the expansionthereupon forces the upper head to a convex position as indicated at 1927. Serial No. 192,183.

5', the metal head in the passing from one position to the other emitting a snapping noise clearly audible to the operator ofthe car.

Theexternal surface of the upper head, when in convex position, is exposed to currents of air, while it is shielded against such currents by wall 3 when in its concave position. This exposure permits the air flowing along the exterior ofthe head to cool the vaporized fluidtherein and causethesame to condense, thus reducing the pressure and allowing the head to snap back to its original position. The alternate vaporization and condensation of the fluid Will produce a series '6 of audible signals which will be maintained either until the fluid below the head 6 is cooled to a point where vaporization su'fiicient to move head 5 upwardly ceases, or until the fluid 7 is so heated to a point where the air 0 on the upper head is unable to condense it suiiiciently to cause this head to return to its normal position. i

In Figs. 2 and 3 we have illustrated a sig naling device in which thesignal is produced by the ringing of a bell.

The radiator cap is shown asconsisting of a threaded tubular section-6, adapted to be detachably connected with the threads of the radiator filling spout, and'provided at its up per end with an outwardly extendingflange' 7 and an inwardly extending flange 8. Within the tubular section is secured a capsule 9 filled with a suitable liquid or a mixture of liquids which will vaporize at the temperature-which it is desiredto indicate, and so formed that such vaporization will move its upper end or head upwardly an appreciable distance. I

Within the central apertureof flange 8 is '90 secured the lower end of apost 10, this end being provided with a'flange 11 seating upon the upper surface of flange 8 and a hollow threaded'shan'k 12 projecting through the aperture of flange 8 and secured therein as by nut 13.

The post may be conveniently made as-illustrated with its upper end 14 concentric with the cap and the threaded shank 12, and the remaining intermediate portion offset.

The upper end of the post is threaded and a bell 15 is screwed thereon, the margin of bell clearing the outer edges of flange 7, the flange end a disc-like head 22 which rests upon the upper head of capsule 9.

Surrounding rod 21 and extending wituin the counterbored recess 18, is a helical spring 23 which retains the rod head against the upper end of the capsule. I

Near the threaded portion of the post is a lug 24 to which is secured, as by rivets, two downwardly diverging springs 25 carrying at their free ends hammers 26 which may be brought intooperative relation with the bell to ring the same. 7 I Y p The operation of this alarm is as follows: l/Vhen the fluid in the capsule becomes vaporized, the upper. end of the capsule is forced upwardlymoving with it, head 22 and rod 21. The upper end of rod 21 is forced between the springs 25 just below lug 24 and wedges these springs apart, so that the springs assume the position shown in dashed lines, in Fig. 2, with the hammers closely adjacent the bell 15. Due to the vibration of the vehicle, the hammers at no time when the engine is running, remain absolutely stationary, but are constantly vibrating throughout a small amplitude. This vibration is suflicient to cause the hammers to impinge upon the bell rapidly, causing the alarm to give the audible signal desired. I

In Fig. 4 is illustrated a signaling alarm similar to that of Figs. 2 and 3 except that the shape of the bell has been changed and only one hammer is used therewith. In this form the capsule, cap, post, and rod are substantially the same as those already described, but the bell 27, instead of being a surface of revolution, is formed to constitute a shelllike ornament, shown as taking the form of a bird in flight. This shell is secured to the top of post 28 by a screw 29. 7 Supported upon the bell as by rivets 30, is a single spring 31 provided at its free end with a hammer 32. This spring passes over the upper end of rod 33, so that upon the rod being moved upwardly by the vaporization of the fluid within the capsule 34,-, the hammer is brought closely adjacent the shell 27 and vibrations imparted to the hammer by the vehicle will cause the same to impinge upon the shell and so give out .the ringing sound whichis'to indicate that theundesired temperature has. been reached by the motor.

The signal of Fig. 5 is similar to that of Figs. 2 and 3 except that it is arranged to give an alarm either when the temperature of the motor is below a predetermined minimum or above a predetermined maximum, the signal being silent between these temperatures. In this signal, the rod 35 is provided at its upper end with an enlarged head 36 and the hammer-supporting springs 37 diverge above and converge below this head as shown. It will be seen that whether the rod moves upwards from its normal position as is the case when the motor becomes too hot, or downwardly, as is the case when the motor becomes too cold, the head will wedge the springs apart, bringing the hammers 38 into bcll ringing position and so producing the alarm; I

While we have described the illustrated embodiments of our invention in some particularity, obviously many others will readily occur to those skilled in the art to which this invention appertains, and we do not, therefore, limit ourselves tothe details shown and described, but claim as our invention all of the embodiments thereof coming within the scope of the appended claims.

lVe claim:

1. An indicator for automotive vehicles comprising two elements adapted to emit moved closely adjacent each other, and a thermostatic device arranged to move one of said elements toward and from the other.

3. A temperature indicator for internal combustion motors which comprises a bell, a hammer therefor, a resilient support for the hammer, and thermo-responsive means associated with the support to move the hammer into ringing relation to the bell.

4. A temperature indicator for internal combustion motors which comprises a bell, a hammer therefor, a resilient support for the hammer so arranged that vibrations from the motor cause the hammer to oscillate, means, engaging the support to hold the hammer in bell-ringing position, and thermo-responsive means to move said first mentioned means out of engagement with the support between two pie-determined temperatures.

5. A temperature indicator for internal combustion motors which comprises a bell, a hammer therefor, a resilient support for the hammer so arranged that vibrations from the car in motion cause the hammer to oscillate, and thermo-responsive means to move the hammer to hell ringing position.

6. A temperature indicator for internal combustion motors which comprises a bell, a hammer therefor, a resilient support for the hammer so arranged that vibrations from the car in motion cause the hammer to oscillate, means engaging the support to hold the hammer in bell-ringing position, and thermoresponsive means to move said first mentioned means out of engagement with the support below a pre-cletermined temperature.

In testimony whereof We hereunto affix our signatures this 11th day of May, 1927.

FREDERICK G. FOLBERTH. WVILLIAM M. FOLBERTH. 

